Code Acquisition in DS/CDMA Systems by Employing a Detector Based on a posteriori Probability Calculation

M. Tahir Abbas KHAN  Nobuoki ESHIMA  Yutaka JITSUMATSU  Tohru KOHDA  

IEICE TRANSACTIONS on Communications   Vol.E88-B   No.10   pp.4047-4055
Publication Date: 2005/10/01
Online ISSN: 
DOI: 10.1093/ietcom/e88-b.10.4047
Print ISSN: 0916-8516
Type of Manuscript: PAPER
Category: Wireless Communication Technologies
code acquisition,  DS/CDMA,  multiuser systems,  a posteriori probability,  

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A detector based on calculation of a posteriori probability is proposed for code acquisition in singleuser direct sequence code division multiple access (DS/CDMA) systems. Available information is used for decision making, unlike conventional methods which only use a part of it. Although this increases the overhead in terms of additional memory and computational complexity, significant performance improvements are achieved. The frame work is extended to multiuser systems and again mean acquisition time/correct acquisition probability performance is superior to the conventional systems although computational complexity is high. An approximate multiuser method with significantly less complexity is also derived.